.nav {
    height: 88px;
    display: flex;
    flex-direction: row;
    align-items: center;
    position: fixed;
    width: 100%;
    z-index: 9999999;
    overflow: hidden;
}

.nav_back {
    margin-left: 32px;
    color: white;
}

.nav_title {
    text-align: center;
    max-width: 400px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    margin: auto;
    font-size: 36px;
    color: #2c2b2b;
    padding-right: 32PX;
    font-weight: 450;
}